(CN) - Thirty-four years after Kathleen Durst's disappearance in Westchester, N.Y., her family claims in court that their former in-law, Robert Durst, hid the body.
Ann McCormack, Carol Bamonte, Mary Hughes and Virginia McKeon filed the lawsuit against Robert Durst on Monday in Nassau County Supreme Court.
McCormack, age 101, is Durst's former mother-in-law, and the three other plaintiffs were sisters of Kathleen, who has not been seen since 1982.
A few weeks before she went missing, Kathleen had begun the process of divorcing Durst and sought medical attention for domestic abuse.
The investigation quickly focused on the husband, whose father was a prominent real estate developer, but Durst had an alibi supported by a friend named Susan Berman.
Shortly after Westchester prosecutors reopened the Durst investigation in 2000, however, Berman was found murdered execution-style in her Los Angeles home.
Durst has been suspected in the murders of several other people who were dismembered, bagged and tossed across the country.
In 2001, Durst was charged in Galveston, Texas, with murdering his elderly neighbor Morris Black. Though Durst admitted to dismembering Black's body and dumping his remains in the ocean, a jury credited Durst's self-defense claims and acquitted him of the murder.
While living in Galveston, Durst posed as a mute woman to avoid being recognized.
"The Jinx: The Life and Deaths of Robert Durst," an HBO documentary that aired in early 2015, has fueled interest in Durst for a new generation of true-crime enthusiasts.
With Los Angeles reportedly eager to have Durst tried there for Berman's murder, Kathleen's family filed their suit in Long Island, where matriarch McCormack lives.
"For the past 33 years, Durst has concealed the whereabouts of Kathleen's body from her next of kin," the complaint states. "Through this action, plaintiffs seek to hold Durst liable for breaching their right of sepulcher by intentionally and knowingly preventing plaintiffs from providing a proper burial for Kathleen."
Durst is currently in a Louisiana jail awaiting trial on a gun charge.
When he went to use the bathroom at the end of filming the HBO documentary, Durst did not turn off his wireless microphone and can be heard saying to himself, "What the hell did I do? Killed them all, of course."
Former Westchester prosecutor Jeanine Pirro recently released a book detailing her investigation of the Durst case titled "He Killed Them All: Robert Durst and My Quest for Justice."
McCormack and her daughters characterize Durst's statement as a "chilling confession."
The family seeks punitive and compensatory damages of $100 million for keeping the secret for so many years of where he hid Kathleen's body, violating their right of sepulcher.
Interestingly, there is no allegation of wrongful death in the lawsuit.
The family is represented by Robert Abrams with Abrams, Fensterman, Fensterman, Eisman, Formato, Ferrara & Wolf in Lake Success, N.Y.
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